<template>
    <div>
      <ul>
        <li v-for=" obj in arr" :key="obj.id"> 
        {{obj.name}}
  <input type="text">
        </li>
        <button @click="fn">点击增加</button>
      </ul>
    </div>
  </template>
  
  <script>
  export default {
    data() {
      return {
        arr: [
          {
            name: '老大',
            id: 50
          },
          {
            name: '老二',
            id: 31
          },
          {
            name: '老三',
            id: 10
          }
        ],
      };
    },
    methods: {
      fn(){
  this.arr.splice(1,0,'我是新来的')
      },
    },
  };
  </script>
  
  <style>
  </style>